Capacitor constructions continue to have increasing aspect ratios in higher generation integrated circuitry fabrication. For example, dynamic random access memory (DRAM) capacitors now have elevations of from 2 to 3 microns, with widths of about 0.1 micron. Further, it is a continuing goal to increase the density of semiconductor devices, with a corresponding goal to reduce the footprint associated with individual devices. As the packing density of capacitor devices becomes increasingly greater, the available surface area for capacitance decreases.
A common capacitor construction is a so-called container device. One of the electrodes of such device is shaped as a container, and subsequently dielectric material and another capacitor electrode are formed within the container. Typically, only the interior surfaces of the containers are being utilized for capacitance surface area. It would be desirable to utilize exterior surfaces of the containers for capacitance as well. Unfortunately, exposure of both the interior and exterior surfaces of a container having a high aspect ratio can render the container structurally weak, and subject to toppling or breaking from an underlying base. It would therefore be desirable to develop methods which enable exterior surfaces of high aspect ratio containers to be utilized as capacitive surfaces while avoiding toppling or other loss of structural integrity of the high aspect ratio containers.
Another type of capacitor structure is a so-called pedestal (or post) device. One of the electrodes of the device is shaped as a pedestal, and subsequently dielectric material and another capacitor electrode are formed over and around the pedestal. If the pedestal is tall and thin, it can be structurally weak and subject to toppling or breaking from an underlying base. It would therefore be desirable to develop methods which avoiding toppling or other loss of structural integrity of pedestals.
Although the invention is, at least in part, motivated by the problems discussed above, it is to be understood that the invention can have applications beyond the addressing of such problems.